1. Field of the Invention
This invention relates generally to a pressure compensating irrigation hose, and more particularly to a pressure compensating hose having an elongate elastomeric member, which, with the hose, forms an irrigation hose having a plurality of pressure compensated emitters.
2. Description of the Prior Art
Agricultural irrigation systems in use today are predominantly flood and sprinkler systems. These systems have numerous shortcomings, including inefficient use of water and fertilizers, high labor and energy costs, pollution of surface and ground waters, and poor uniformity of water application on steep or uneven terrain.
Drip irrigation systems are being developed and adopted to address the above-noted problems. There are two major types of drip irrigation systems currently in use. The first involves use of discrete emitters installed either internally (In-Line) or externally (On-Line) to the hose. These emitters have passageways through which the water must pass, thereby regulating the water flow rate through the emitter. Such emitters may be pressure-compensating or non-pressure-compensating.
Another type of drip irrigation system employs a hose having a continuous emitter such as the Aqua-TraXX(copyright) hose of The Toro Company. Such hose includes the use of a continuous non-elastic strip which, in conjunction with the hose, forms a plurality of emitters. Perforations are then formed in the outside surface of the hose into the outlet of the emitter. However, such hose is not pressure compensating, and is therefore not suitable for use on steep or non-uniform terrain.
U.S. Pat. Nos. 4,984,739 and 5,333,793 are examples of a hose having a continuous emitter and also include a pressure compensating system. The present invention provides for a pressure compensating drip emitter irrigation hose which utilizes a continuous elastomeric strip member having a hardness which is less than that of the hose.
In one embodiment, the invention is a pressure compensating drip irrigation hose for distributing water. The hose has an inner wall having an inner surface which defines a main water passageway. A continuous elastomeric strip member is operatively connected to the inner surface. The continuous elastomeric strip member and the inner surface define a plurality of emitter units. The continuous elastomeric strip member has a bottom wall operatively connected to first and second spaced elongated side members. The bottom wall, side members and inner surface define an emitter water passageway. Each emitter unit comprises an inlet, wherein water from a main water passageway enters the emitter unit through the inlet. A pressure reducing section is downstream from the inlet, wherein water flowing through the emitter is slowed and water pressure is reduced. A pressure responsive section is downstream from the pressure reducing section, wherein with increased pressure in the main water passage, the bottom wall deflects towards the inner surface, thereby decreasing the size of the emitter water passageway. An outlet is formed in the hose wall, the outlet is in fluid communication with the emitter water passageway and downstream from the pressure responsive section.
In another embodiment, the invention is a pressure compensating drip irrigation hose for distributing water. The hose has a wall having an inner surface, the inner surface defining a main water passageway. A continuous elastomeric strip member has a hardness less than that of the hose, the continuous elastomeric strip member is operatively connected to the inner surface and defines an emitter water passageway. Each emitter unit comprises a water inlet, wherein water from the main water passageway enters the emitter through the inlet. A pressure reducing section is provided, wherein water flowing through the emitter is slowed and water pressure is reduced. In a pressure responsive section, the emitter also includes a pressure responsive section, wherein with increased pressure in the main water passageway, the bottom wall deflects towards the inner surface, thereby decreasing the size of the emitter water passageway. An outlet is formed on the hose wall, the outlet is in fluid communication with the emitter water passageway and a plurality of first preformed members are formed in the outlet section, whereby the pressure responsive section is more sensitive to pressure than the outlet section. In addition, a plurality of second preformed members are formed in the pressure reducing section, whereby the pressure reducing section is less responsive to pressure than the pressure responsive section.